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getUserMedia和WEBUSB在同一设备窗口上

webusb getusermedia usb google-chrome windows
  •  1
  • Fabiano Taioli  · 技术社区  · 7 年前

    我们正在开发一个基于Chrome(旧的USB API现在迁移到WEBUSB)和网络摄像头的项目。USB网络摄像头有一个用于拍照的按钮。在MAC和Linux中,我可以使用getUserMedia()显示网络摄像头的实时视频,同时我可以使用Web USB API与设备通信以检测按键。

    N、 B。

    Linux lsusb转储: 

    Bus 001 Device 008: ID a168:0872 AnMo Electronics Corporation 
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass          239 Miscellaneous Device
  bDeviceSubClass         2 
  bDeviceProtocol         1 Interface Association
  bMaxPacketSize0        64
  idVendor           0xa168 AnMo Electronics Corporation
  idProduct          0x0872 
  bcdDevice           20.01
  iManufacturer           1 ANMO Electronics Corporation
  iProduct                2 Dino-Lite Premier
  iSerial                 3                         
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength          509
    bNumInterfaces          2
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0x80
      (Bus Powered)
    MaxPower              500mA
    Interface Association:
      bLength                 8
      bDescriptorType        11
      bFirstInterface         0
      bInterfaceCount         2
      bFunctionClass         14 Video
      bFunctionSubClass       3 Video Interface Collection
      bFunctionProtocol       0 
      iFunction               2 Dino-Lite Premier
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass        14 Video
      bInterfaceSubClass      1 Video Control
      bInterfaceProtocol      0 
      iInterface              2 Dino-Lite Premier
      VideoControl Interface Descriptor:
        bLength                13
        bDescriptorType        36
        bDescriptorSubtype      1 (HEADER)
        bcdUVC               1.00
        wTotalLength           80
        dwClockFrequency        6.000000MHz
        bInCollection           1
        baInterfaceNr( 0)       1
      VideoControl Interface Descriptor:
        bLength                18
        bDescriptorType        36
        bDescriptorSubtype      2 (INPUT_TERMINAL)
        bTerminalID             1
        wTerminalType      0x0201 Camera Sensor
        bAssocTerminal          0
        iTerminal               0 
        wObjectiveFocalLengthMin      0
        wObjectiveFocalLengthMax      0
        wOcularFocalLength            0
        bControlSize                  3
        bmControls           0x000200a2
          Auto-Exposure Mode
          Focus (Absolute)
          Iris (Absolute)
          Focus, Auto
      VideoControl Interface Descriptor:
        bLength                11
        bDescriptorType        36
        bDescriptorSubtype      5 (PROCESSING_UNIT)
      Warning: Descriptor too short
        bUnitID                 3
        bSourceID               1
        wMaxMultiplier          0
        bControlSize            2
        bmControls     0x0000147f
          Brightness
          Contrast
          Hue
          Saturation
          Sharpness
          Gamma
          White Balance Temperature
          Power Line Frequency
          White Balance Temperature, Auto
        iProcessing             0 
        bmVideoStandards     0x1d
          None
          PAL - 625/50
          SECAM - 625/50
          NTSC - 625/50
      VideoControl Interface Descriptor:
        bLength                29
        bDescriptorType        36
        bDescriptorSubtype      6 (EXTENSION_UNIT)
        bUnitID                 4
        guidExtensionCode         {2652215a-8932-5641-894a-5c557cdf9664}
        bNumControl            16
        bNrPins                 1
        baSourceID( 0)          3
        bControlSize            4
        bmControls( 0)       0xff
        bmControls( 1)       0xff
        bmControls( 2)       0xff
        bmControls( 3)       0xff
        iExtension              0 
      VideoControl Interface Descriptor:
        bLength                 9
        bDescriptorType        36
        bDescriptorSubtype      3 (OUTPUT_TERMINAL)
        bTerminalID             2
        wTerminalType      0x0101 USB Streaming
        bAssocTerminal          0
        bSourceID               4
        iTerminal               0 
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0008  1x 8 bytes
        bInterval               9
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass        14 Video
      bInterfaceSubClass      2 Video Streaming
      bInterfaceProtocol      0 
      iInterface              0 
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x0000  1x 0 bytes
        bInterval               1
        INTERFACE CLASS:  0f 24 01 02 67 01 82 00 02 01 01 00 01 00 00
        INTERFACE CLASS:  0b 24 06 01 05 00 01 00 00 00 00
        INTERFACE CLASS:  1e 24 07 01 00 80 02 e0 01 00 00 08 ca 00 00 08 ca 00 60 09 00 15 16 05 00 01 15 16 05 00
        INTERFACE CLASS:  1e 24 07 02 00 40 01 f0 00 80 00 02 32 80 00 02 32 00 58 02 00 15 16 05 00 01 15 16 05 00
        INTERFACE CLASS:  1e 24 07 03 00 a0 00 78 00 a0 00 00 8c a0 00 00 8c 00 96 00 00 15 16 05 00 01 15 16 05 00
        INTERFACE CLASS:  1e 24 07 04 00 00 05 00 04 00 00 19 00 00 00 19 00 00 00 28 00 20 a1 07 00 01 20 a1 07 00
        INTERFACE CLASS:  1e 24 07 01 00 80 02 e0 01 00 00 08 ca 00 00 08 ca 00 60 09 00 15 16 05 00 01 15 16 05 00
        INTERFACE CLASS:  1b 24 04 02 05 59 55 59 32 00 00 10 00 80 00 00 aa 00 38 9b 71 10 01 00 00 00 00
        INTERFACE CLASS:  1e 24 05 01 00 80 02 e0 01 00 00 08 ca 00 00 08 ca 00 60 09 00 15 16 05 00 01 15 16 05 00
        INTERFACE CLASS:  1e 24 05 02 00 40 01 f0 00 80 00 02 32 80 00 02 32 00 58 02 00 15 16 05 00 01 15 16 05 00
        INTERFACE CLASS:  1e 24 05 03 00 a0 00 78 00 a0 00 00 8c a0 00 00 8c 00 96 00 00 15 16 05 00 01 15 16 05 00
        INTERFACE CLASS:  1e 24 05 04 00 00 05 00 04 00 00 19 00 00 00 19 00 00 00 28 00 20 a1 07 00 01 20 a1 07 00
        INTERFACE CLASS:  1e 24 05 01 00 80 02 e0 01 00 00 08 ca 00 00 08 ca 00 60 09 00 15 16 05 00 01 15 16 05 00
        INTERFACE CLASS:  06 24 0d 00 00 00
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       1
      bNumEndpoints           1
      bInterfaceClass        14 Video
      bInterfaceSubClass      2 Video Streaming
      bInterfaceProtocol      0 
      iInterface              0 
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            5
          Transfer Type            Isochronous
          Synch Type               Asynchronous
          Usage Type               Data
        wMaxPacketSize     0x13fc  3x 1020 bytes
        bInterval               1
Device Qualifier (for other device speed):
  bLength                10
  bDescriptorType         6
  bcdUSB               2.00
  bDeviceClass          239 Miscellaneous Device
  bDeviceSubClass         2 
  bDeviceProtocol         1 Interface Association
  bMaxPacketSize0        64
  bNumConfigurations      1
can't get debug descriptor: Resource temporarily unavailable
Device Status:     0x0000
  (Bus Powered)
    1 回复  |  直到 7 年前
        1
  •  1
  •   Reilly Grant    7 年前

    基于 lsusb -v 上面我可以看到,这个设备有一个由两个USB接口组成的单一功能。接口关联描述符(IAD)向主机操作系统发出信号,表明这两个接口是相关的,并且为了驱动程序绑定的目的,操作系统(如Windows)将它们视为单个接口。

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